Epson TM-T88V-i

20
Wireless LAN cable set (optional) LED
With the LED on the wireless LAN unit, you can check the communication status of the product.
LED Description
On The wireless LAN unit is not connected to the product. Or the product power is OFF.
Off This wireless LAN unit is connected to the product and is in operation. 
This unit is not communicating on a network.
Flashing
This wireless LAN unit is connected to the product and is in operation. 
This unit is communicating on a network.
LED (Green)